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Reg. 365 A, Reg. 365 B
STEAM RECEIVERS, SEPARATORS, CATCH WATERS,
ACCUMULATORS AND SIMILAR VESSELS
Materials
| 1) |
Plates, Bars, Sections and
Rivets.- Materials for plates, bars, sections and
rivets used in the construction of Steam Receivers, Separators,
Catch Waters and Similar Vessels shall comply in all respects
with the requirements of relevant regulations of Chapters
II and V,
depending upon the mode of construction. |
| 2) |
Branches, Bosses and Drain
Pockets.- Branches, bosses and drain pockets may be
solid forged, fabricated by fusion welding, machined from
solid bars or made from tubes. |
| 3) |
Flanges.- Materials
for flanges shall comply with the appropriate provisions
of Regulation 353. |
| 4) |
Forgings.- Materials
for flanges shall comply with the appropriate provisions
of Regulation 243. |
| 5) |
Steel Castings.- Steel
castings for shells or pressure parts of shell shall comply
with Regulations 73
to 80 |
Reg. 365 B
Construction and Workmanship
| 1) |
Shell Ends:– Shall
ends formed separately from the shell may be dished or
flat. Alternatively, the ends of the shell may be forged
down and closed by manhole doors or by plugs or branches
welded-in. |
| 2) |
Dished Ends:- Each dished
end shall be made one from rolled plate. If this is impracticable,
owing to the large diameter, the dished end plate may
be made from two plates fusion butt welded together, and
in such cases the line of weld shall be parallel to the
horizontal axis of the vessels and the weld shall be radiographed
after forming. The shape of Dished End shall conform to
the requirements of Regulation
275. Dishing and peripheral flanging shall be done
by machine. Coiled flanging shall not be adopted. All
plates which have been dished, flanged, or locally heated
shall afterwards be efficiently heat treated for the purpose
of relieving internal stresses, unless during the last
stage of manufacture, they have been uniformly heated
throughout to a suitable temperature. Care shall be taken
to see that the flanges are cylindrical of good surface
and free from local irregularities.
Where flats are pressed in dished ends for the attachment
of connections they shall be formed with an ample radius
at the junctions of the flat and curved surfaces and shall
be free from sharp corners and tool marks.
Dished ends shall be attached to the cylindrical part
of the shell by one of the following methods:-
| i) Riveting:- Dished ends
shall be machined to fit closely into the cylindrical
part of the shell and flogging or hammering in the
fitting of ends shall not be adopted. The caulking
edges of all flanged plates shall be machined or
flame cut by machine. |
| (ii) Welding with butt joints
of the single or double U or V type:- Where
the internal diameter of the shell in 24 ins. or
over, the joints shall, in all cases, be welded
from both sides of the plate. Where the internal
diameter of the shell is less than 24 ins., the
joints may be welded from one side only, when efficient
welding from inside is considered impracticable. |
| (iii) In
the construction of unfired boilers when the
dished ends do not form of the heating surface,
cold spun dished ends conforming to IS:2825 may be
used. |
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| 3) |
Flat Ends:- Flat ends
shall be of forged steel or plate steel and shall be welded
to the cylindrical part of the shell or bolted to flanges
which shall be attached to the cylindrical part of the
shell in accordance with Regulation
356 or 357.
The attachment of flat ends shall be by one of the methods
shown in Figure Nos. 365/2,
365/2A, 365/3 and
365/4.
When ends are attached as shown in Figure 365/4, welding
shall be from both side of the shell plate where practicable.
Where welding is done from one side only, care shall be
taken to ensure full penetration using backing strips. |
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